The study of The study of ChemicalChemical & & PhysicalPhysical PropertiesProperties and and ChangesChanges of Matter of Matter

ChemistryChemistry

Problem!Problem!• How can you identify a specific

substance?

Solution!!!Solution!!!

We use Properties to identify them!

I know, I know… what are properties?

Properties of Matter

• Properties are the “identifying characteristics” of substances.

– All substances have their own properties unlike any other substance.

– You can identify all substances if you know enough of the properties

Properties of Matter

• There are two properties of Matter:– Physical & Chemical

Physical Properties

• Physical properties of a substance are like the physical characteristics that help others identify you.

– It’s what makes you – unique!

Let’s give it a shot in REAL LIFE!

Problem!!!Problem!!!• Just like twins, sometimes the substances all

look the same – how can you tell which is which then?

Chemical Properties Recap

• Chemical:– How a substance reacts with other

substances.

+ =

Fizzing

Let’s see just how that works

• On the next slide is a table of two twins, Megan & Emily, and what is known about their feelings towards other people.

• See if you can use this information to identify the twin in question.

BFF! She’s a Witch!

Whoa –

He’s HOT!

Don’t like the “Go-T”!!!!

Just Friends. I think she’s nice.

Nice Eyes. Love the Fuzz.

A Bit Extreme

Shy & Nice

Here’s the Scenario Here’s the Scenario

+ =

+ =

Who is it? Megan or Emily?Who is it? Megan or Emily?

?

?

It’s It’s

MeganMegan!!After running a few tests – and seeing how she “reacts” to “other people”, you can tell which twin she really is.

The same is true with substances that look like other substances. Try to react it with other substances to see what happens.

She’s a Witch!

Don’t like the “Go-T”!!!!

I think she’s nice.

Love the Fuzz.

A Bit Extreme

Shy & Nice

Analogy

• Physical properties are like describing a person or substance.

• Chemical properties are like describing a substances relationship (or reaction) with another substance.

Chemical & Physical Change

• Properties help us to identify substances – but when we actually DO / TRY something, and it actually changes as a result – we say it under-went a chemical or physical change.

– It all depends on whether or not the substance changed into something new or not.

Definitions• Physical Change:

– Any time you alter the substance, but it’s still the same substance.

• Indicators of a Physical Change:– Phase change– Mixing (Not reacting)– Change in shape or size– Expected Change of ColorAny kind of change that does not change what it is

Definitions

• Chemical Change:– Any time you react the substance with another

substance – and it changes into another substance.

• Indicators of a Chemical Change:– Fire– Change of Energy: i.e. Heat, Light & Sound– Bubbling - production of gas– Unexpected Change of Color– Precipitate (getting a solid from mixing two liquids)

PhysicalPhysical ChemicalChemicalDescribes the physical characteristics of the substance.

–Hardness, texture, state of matter, shape, size, etc.

Describes how the substance reacts with other substances.• Iron + Oxygen Rust

• Silver + Sulfur Tarnish• Gold + Oxygen No change• Paper + Oxygen (fire) Ash

A physical alteration of the substance but still the same substance.

Indicators:–Phase change–Mixture–Shape / Size change–Expected Color Change

Two substances interact to form another substance.

Indicators:–Fire–Light, Sound, Heat–Producing a gas (Fizz/Bubble)–Unexpected color change–Precipitate

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Cha

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Physical Change Physical Change IndicatorsIndicators

Chemical Change Chemical Change IndicatorsIndicators

• The substance has not changed into something new

• The physical appearance may have changed, but the substance is still the same.

• There is no energy conversion

• The substance has reacted with another substance.

• The substance has changed into another substance.

• Energy has been converted from one form into another.

Physical Change Physical Change Indicator wordsIndicator words

Chemical Change Chemical Change Indicator wordsIndicator words

•Twisted

•Bent

•Crushed

•Froze

•Boiled

•Melted

•Condensed

•Dissolved

•Burned

•Flammable

•Fire

•Combusted

•Cooked

•Fizzed / bubbled

•Changed color

•Decomposed